Pneumatic-tire construction



atented Aung. 10, 119.26.

UNITED STATES 1,595,313 PATENT OFFICE.

ROBERT C. IIIERCE, OF. BELLEVILLE, NEW JERSEY, ASSIGNOR TO JOHN R. GAMMETER. OF AKRON, ORIO.

PNEUMATIC-TIRE CONSTRUCTION.

Application ledliarch 30, 1923. Serial No. 628,688.

This inventionrelates to the construction of pneumatic automobile tires of the straight side or inextensible bead type, it being one of the objects of the invention to improve `upon the bead structure and particularly the reinforcement contained in the bead and designed to impart inextensibility to it.

It will be appreciated by those familiar with the art that beads of the type described Should be reinforced by an inextensible medium which should be somewhatflexibleand should be capable of uniting with the rubber composition which forms the body or major portion of the bead. Beads of this 15 type are usually triangular .in cross-section,

or substantially so, and are provided with a mass of circumferentially extending wires which are embedded within, and vulcanized to, the rubber of the bead. Heretofore the general practice has been to make use of a tapewhich is composed of'a plurality of wires extending back and forth across the tape and braided together so that the meshes are in the general form of elongated diamonds with their long axes in the direction of the circumference of the bead.

Braided tape of the type described has been used for a considerable period in the form of a straight-side tire where the triangular bead is employed, but it has had disadvantages, especially as it requires eX- pensive and complicated machinery to manufactureit and as it has a certain stretchabilit due to the diamond-shaped formation of t e weave.

In my prior application, Serial No. 530,- 801, filed January 21, 1922, I have shown and described a form of tape which obviates all of the disadvantages attendant upon the use of the prior diamond-shaped mesh or braided wire. The present invention is based upon the said prior disclosure, but aims to add thereto certain advantages as will be apparents, l

The present invention has for its object the provision of a larger number of wires in a width of tape than that shown in the prior application, whereby greater tensile strength may be imparted to the bead structure.' It

5 erted in the bead-curing or tire-curing mold.

is also an object of this invention to place` In the drawing is shown one embodiment of this improvement invention in which Figure 1 is a view of a portion of the wire forming the subject matter of the invention;

Fig. 1a is a side elevation thereof;

Fig. 2 is a cross-section on the line 2 2 of Fig. 1;

Fig. 3 is a side elevation of the wire. as coiled or wrapped into the plurality of layers in which it is received in the tire;

Fig. 4 is a. view showing the manner in which the elements of the bead are assembled;

Fig. 5 is a. view showing the bead in the curing' mold;

Fig. 6 is a side elevation of the completed bead; and

Fig. 7 is a cross-section through one bead portion of a pneumatic tire casing showing the improved bead in position.

The wire reinforcement is shown in Figs. 1, l, 2, and 8. It will be seen that it contains a large number of parallel or circumferential warp wires 1 which are held together in the form of a tape by a crossing 80 wire 2. The outer circumferential or selvage4 wires l may be of greater tensile strength than the inner or filling wires, al though this is not essential. It will be noted that the wires are placed closely together across the tape, in factythe object of the present invention is to completely fill the. tape from edge to edge with longitudinal wires which are placed in substantial contact with one another, or the wires may be said to have zero spacing.

The crossing wire 2 is woven back and forth across the longitudinal or warp wires under tension in the zigzag position shown in Fig. 1, and while it is of higher gage than the warpwires it passes in substantial- 1y` straight lines from edge to edge of the tape Ywhereby a considerable wave or undulation is imparted to each surface of the tape as shown in Fig. 1'". These waves in the 100 warp wire serve to 'Ve a large anchorage to the rubber which 1s to be appliedaround the reinforcement. If the outer wires are stier than the inner or filling wires the outer wires will be straight as shown in Fig. 105 1. If the parallel wires are of equal strength throughout, all ofthe wires will assume an undulatory character.

The subsequent steps in the manufacture of the bead are shown' in Figs. 4, 5 and 6. 11

The hoop or ring of wire tape 3 (shown in Fig. 3) which may or may not be insulated, or coated with rubber, is formed or placed on a form or Wheel i and over a strip of fabric 5 which is designed to form the cover ot the bead. A mass ot" rubber 6 is placed on or about the bead ring and the cover is folded over as shown in Fig. Il. The soft, unvulcanized bead is now placed in a mold and given a partial cure which brings it to substantially rigid condition and imparts the triangular cross-section thereto. The mold is shown at 7 and the partially vulcanized bead is shown at 8 in Figs. 5 and 6.

rl`he bead is now ready to be placed in a tire. A portion of the tire with the improved bead incorporated therein is shown at 9 in Fig. 7.

lt will be observed by an inspection of the drawing and from the description ot the invention that the Wire tape or bead reinforcement comprises the largest number oi Wires Which it is possible. to place in the Width of tape. They are in contact through that portion or the tape where the crossing wire does not intervene. The crossing Wire holds the Warp wires in their proper position and also places Waves or even undulations on the upper and lower surfaces of the tape which assist materially in affording a grip or foundation for the rubber, thereby increasing the tenacity with which the rubber and the Wire reintorcement are bound together. As the Wires are in contact across the tape, it is impossible to easily crush the tape y lateral pressure.

ln carrying out the objects ot the present invention it is not essential that all ot the details recited herein be retained, it being rossible to embody the invention in different orms and with modifications and variations, as will be understood by those familiar' with the art.

What l claim is:

l. ln a tire construction, a bead, said bead embodying a reinforcement adapted to im-r part inertensibility thereto.J said reinforcement comprising a plurality or arallel warp Wires in contact `with one anot er and a ller Wire Woven back and forth across the Warp wires and serving to maintain them iny 3. ln a tire constructidn, a beadpsaid bead l embodying a reinforcement in the torni ot a Wire tape ada ted to impart inextensibility to the bead. sai tape comprising a plurality of Warp wires in contact with one another and a continuous iller Wire in zigzag diagonal vcourses tying the Warp` wires together.

4. ln a tire construction, a bead, said bead embodying a reinforcement in the torni of a wire tape adapted to impart inextensibility to the bead, said tape comprising a plurality of Warp `Wires in contact with one another and a continuous liller `wire in zigzag diagonal courses tying the Warp Wires together and forming the surfaces ot the tape inun i dulations or waves.

5. A tire bead comprising a ring-shaped body substantially triangular in cross-secn tion and composed ot a rubber composition and a reinforcement for said bead parallel tc one side thereof and comprising a Wire tape Wrapped in a plurality ot convolutions, the wire tape being tormed'from a plurality ot parallel Warp wires placed in contact vvith one another and a continuous crossing Wire interwoven with said Warp `Wires and serving to maintain them in parallel relationship.

6. A tire bead comprising a ring-'shaped body substantially triangular in cross-section and composed ot a vulcanized rubber composition and a reinforcement for said bead, said reinforcement comprising a `Wire tape formed from a plurality of parallel Warp Wires in contact with one another and crossing wire interwoven with said warp wires.

'sonner o. riesca. 

